The use of immunohistochemistry in an oral pathology laboratory.

Immunohistochemistry has become part of normal routine diagnostic work in the Stomatology Unit, Institute for Medical Research, Kuala Lumpur. Of 9523 cases received from the year 2000 to 2005, 197 cases (2.1%) required immunohistochemical staining. These cases ranged from benign to malignant lesions. They include lymphomas (n=41), epithelial tumours (n=29), neural lesions (n=21), fibroblastic/myofibroblastic tumours (n=16), small round cell tumour (n=11), vascular tumours (n=4), smooth muscle tumours (n=4), myxomatous tumours (n=4) and skeletal muscle tumours (n=1). In most of the cases (69.5%), immunohistochemical staining was mandatory to reach a definite diagnosis, while 60 cases (30.5%) required immunohistochemistry in confirming the diagnosis. In 32 cases (16.2%), definitive diagnosis could not be made due to the small size of the specimens received or the results of immunohistochemistry were inconclusive. Standardization of techniques, competent medical laboratory technologists and sufficient budget allocation are important in producing a high quality immunohistochemistry service.